Algebra
- If (x – 2) (x – p) = x2 – ax + 6, then the value of (a – p) is
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(x – 2) (x – p) = x2 – ax + 6
⇒ x (x – p) –2 (x – p)
= x2 – ax + 6
⇒ x2 – px – 2x + 2p = x2 – ax + 6
⇒ x2 – x (p + 2) + 2p
= x2 – ax + 6
∴ p + 2 = a
(comparing respective co-efficients)
⇒ a – p = 2Correct Option: C
(x – 2) (x – p) = x2 – ax + 6
⇒ x (x – p) –2 (x – p)
= x2 – ax + 6
⇒ x2 – px – 2x + 2p = x2 – ax + 6
⇒ x2 – x (p + 2) + 2p
= x2 – ax + 6
∴ p + 2 = a
(comparing respective co-efficients)
⇒ a – p = 2
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which of the following best approximates the circumference of circle P ?If 1 + x2 represents the redius of circle P and 1 + x = 17, x2 x
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1 + x = 17 x
On squaring both sides,x + 1 2 = 172 x ⇒ 1 + x2 + 2 = 289 x2 ⇒ 1 + x2 = 289 − 2 = 287 x2
= radius of the circle
∴ Circumferece of circle = 2πr
= 2 × 287 × π
= 574π unitsCorrect Option: C
1 + x = 17 x
On squaring both sides,x + 1 2 = 172 x ⇒ 1 + x2 + 2 = 289 x2 ⇒ 1 + x2 = 289 − 2 = 287 x2
= radius of the circle
∴ Circumferece of circle = 2πr
= 2 × 287 × π
= 574π units
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If a = 1 , find the value of the expression (2a − 5b) b 2 (5a + 3b)
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a = 1 b 2 = 2 × 1 − 5 2 5 × 1 + 3 2 = 1 − 5 = − 4 × 2 5 + 3 5 + 6 2 −8 11 Correct Option: C
a = 1 b 2 = 2 × 1 − 5 2 5 × 1 + 3 2 = 1 − 5 = − 4 × 2 5 + 3 5 + 6 2 −8 11
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If a + 1 = 1 and b + 1 = 1 then c + 1 is equal to : b c a
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a + 1 = 1 b ⇒ a = 1 – 1 = b − 1 b b ∴ 1 = b a b − 1 Again, b + 1 = 1 c ⇒ 1 = 1 – b c ⇒ c = 1 1 – b ∴ c + 1 = 1 + b a 1 – b b − 1 = 1 − b = 1 – b = 1 1 – b 1 – b 1 – b Correct Option: A
a + 1 = 1 b ⇒ a = 1 – 1 = b − 1 b b ∴ 1 = b a b − 1 Again, b + 1 = 1 c ⇒ 1 = 1 – b c ⇒ c = 1 1 – b ∴ c + 1 = 1 + b a 1 – b b − 1 = 1 − b = 1 – b = 1 1 – b 1 – b 1 – b
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The value of a + b is a − b b − a
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Expression = a + b a − b b − a = a − b a − b a − b = a − b = 1 a − b Correct Option: D
Expression = a + b a − b b − a = a − b a − b a − b = a − b = 1 a − b